1. Field of the Invention
This invention relates to the conducting of selective reactions for the production of aromatics. More particularly, the present invention concerns carrying out such reaction by the utilization of a catalyst comprising a novel class of zeolites in contact with large heterocyclic nitrogen containing organic compounds.
2. Description of the Prior Art
The novel class of zeolites characterized by a silica to alumina mole ratio of at least 12 and a constraint index in the approximate range of 1 to 12 has been found to be extremely useful as an active catalyst component in conducting various selective and shape-selective reactions. This class of zeolites shall hereinafter be referred to as "ZSM-5 class zeolites" and shall mean to include ZSM-5 zeolite and/or other zeolites in the class, e.g., ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-38, etc.
Selective reactions catalyzed by ZSM-5 class zeolites include the alkylation of aromatics, e.g., selective production of para dialkyl substituted benzenes, selective ethylation of benzene and mono alkyl benzenes, and the selective production of para-xylene by the methylation of toluene; disproportionation of toluene (2 Toluene.fwdarw.Benzene+Xylene); xylene isomerization; and alcohol/ether conversion to hydrocarbons; e.g. methanol to gasoline range product, just to name a few.
U.S. Pat. Nos. 3,751,504 and 3,751,506 and literature articles such as J. Catalysis, 61, 477 (1980) generally describe vapor phase alkylation of aromatic hydrocarbons with olefins, e.g., benzene with ethylene, in the presence of a ZSM-5 class zeolite catalyst.
The selective production of alkyl substituted benzene compounds including para dialkyl substituted benzenes and selective ethylation of mono alkyl benzenes over ZSM-5 class zeolites is generally described in the following U.S. Pat. Nos. 4,086,287; 4,094,921; 4,100,217; 4,104,319; 4,117,024; 4,117,026; 4,127,616; 4,128,592; 4,143,084; and 4,136,128.
The selective production of para-xylene by the methylation of toluene in the presence of ZSM-5 class zeolites is given in such U.S. Pat. Nos. as 3,965,207; 4,049,738; 4,080,395; and 4,080,396 and in J. Amer. Chem. Soc., 101, 6783 (1979). Modification of ZSM-5 class zeolites for this reaction utilizing metal and metal oxides, e.g., boron, antimony oxide, magnesium and phosphate compounds, is disclosed in the following U.S. Pat. Nos. 4,029,716 (boron); 4,067,920 (boron); 4,078,009 (boron); 4,067,919 (antimony oxide); 4,113,788 (magnesium); 4,158,024 (magnesium); 4,034,053 (magnesium); and 4,152,364 (phosphate compound). Pretreatment of ZSM-5 class zeolites for the selective production of p-xylene is described in U.S. Pat. No. 3,965,209 (steam treatment); U.S. Pat. No. 3,965,210 (surface of catalyst modified by contact with a polymer made-up of metacarbonate units connected by siloxane units); and U.S. Pat. No. 4,001,346 (precoking).
Disproportionation of toluene over ZSM-5 class zeolites is generally described in the following U.S. Pat. Nos. 4,011,276; 4,016,219; 4,052,476; 4,097,543; 4,098,837; 4,160,788; and 4,182,923. Many of these toluene disproportionation patents disclose the use of metal, e.g. phosphorous and magnesium, with the ZSM-5 class zeolite.
The utilization of ZSM-5 class zeolites for xylene isomerization is described in the following U.S. Pat. Nos. 3,856,871; 3,856,873; 4,101,596; 4,152,363 and 4,163,028.
The conversion of alcohols and/or ethers to valuable hydrocarbons, e.g., olefins and/or gasoline range material, in the presence of ZSM-5 class zeolites is generally disclosed in the following U.S. Pat. Nos. 3,894,103; 3,894,106; 3,894,107; 3,899,544; 3,928,483; 3,998,899; 4,083,888; and 4,083,889. Disclosure of this nature is also found in numerous scientific publications such as J. Catalysis 47, 249 (1977); J. Catalysis 53, 40 (1978); and J. Catalysis 61, 155 (1980).
In many of these aforementioned patents, substances such as P, Mg, SiO.sub.2 and C are used to poison binder activity and to increase diffusion constraints. It is one object of this invention to produce useful materials such as vinyl toluenes without resorting to the use of such substances. It is another object of this invention to provide a useful technique for further improving the selectivity of zeolite catalysts which do contain such substances as P. Mg, SiO.sub.2, C, etc. It is yet another object of this invention to provide a novel process for conducting selective reactions for the production of aromatics.